refactored linkall script

You were doing a little bit of extra work in this script so I simplified things a little. 

If you run `npm link ../<module dir>` inside of your project, it will automatically create a global link, local link and make sure to run `npm install`. See the bottom of https://npmjs.org/doc/link.html

Also, You only need to do this at the project level, and not in each module, because require will always check the root `node_modules`, even in modules farther down. See https://npmjs.org/doc/dedupe.html for more info. 

Finally, I made a **bold** assumption here. I like everything in `~/src` like had originally setup.  I would like to setup the practice of having all the apostrophe modules in `~/src/apostrophe` folder (see line 18). This keeps `src` a little tidier and make it really easy to open up everything in one sublime window (`cd ~/src/apostrophe; subl .`)